It is state of the art to use different kinds of heat exchangers for different purposes. Usually, heat exchangers are used to recover heat energy from one fluid or medium into another one. This kind of heat energy is called sensible energy. The heat energy or sensible energy of one fluid, normally air, is recovered into another one which is running adjacent, e.g. parallel, counter or cross flow, to the first where the fluid is at lower temperature. By inverting fluid flows, the exchange between the two will generate a cooler fluid. Heat exchangers used for sensible energy recovery are usually made of metal or plastic plates. There are different types as there can be cross flow, parallel flow or counter flow configurations. The plates are defining flow channels between themselves so that the fluids can flow between the plates. Such devices are e.g. used in residential and commercial ventilation (HRV).
Another type of energy exchangers refers to the so called latent energy, which is contained in the air moisture. To exchange the latent energy, it is known to use desiccant coated metal or plastic substrates or membranes made from desiccant impregnated cellulose or polymer. Between plates made from cellulose or polymer, air passages are defined or created to allow the fluids to pass along the surface of the plates, thereby transferring moisture from one fluid to the other one. As the membranes usually have no structural strength, it is known to combine the membranes with frames or grids which thereby define openings between the membranes.
In case of a combination of the above, the energy exchangers are called enthalpy exchanger. Those enthalpy exchangers allow for the exchange of sensible and latent energy, resulting in total energy recovery.
Membrane materials as currently available are delivered by the roll. The membrane material is the most critical part of an enthalpy exchanger. The membrane must be fixed and sealed to a kind of grid or frame and arranged in a way to allow for a fluid to flow between each membrane layer. So, it is obvious that enthalpy exchangers of the known art are a compromise. They will usually lose in sensible energy to gain in latent energy as a result of the selective scope and characteristics of currently used membranes.
Such a heat exchanger built from respective elements is e.g. WO 02/072242 A1. On grids respective membranes made of fibers are positioned. The grids are stacked thereby altering the direction of the plates in order to create different air flow directions.
The present invention aims at improving on some of the shortcomings of current heat/enthalpy exchangers.